I had a C3 lower with the same issue. I just left it as it was...no big deal as long as you remember it while disassembling
Does the buffer retainer pin work at all in this condition or does the buffer pop out every time you shotgun the upper?
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
I had a C3 lower with the same issue. I just left it as it was...no big deal as long as you remember it while disassembling
It can be a difference in the tooling as well. As the tools dull they will produce parts with smaller holes. Its amazing the difference a couple of thousandths can make when fitting parts together.